1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
|
/* lzo1b_cm.ch -- implementation of the LZO1B compression algorithm
This file is part of the LZO real-time data compression library.
Copyright (C) 2011 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2010 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2009 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The LZO library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The LZO library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with the LZO library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
http://www.oberhumer.com/opensource/lzo/
*/
/* WARNING: this file should *not* be used by applications. It is
part of the implementation of the library and is subject
to change.
*/
/***********************************************************************
// code the match
************************************************************************/
#if (DD_BITS == 0)
/* we already matched M2_MIN_LEN bytes,
* m_pos also already advanced M2_MIN_LEN bytes */
ip += M2_MIN_LEN;
assert(m_pos < ip);
/* try to match another M2_MAX_LEN + 1 - M2_MIN_LEN bytes
* to see if we get more than a M2 match */
#define M2_OR_M3 (MATCH_M2)
#else /* (DD_BITS == 0) */
/* we already matched m_len bytes */
assert(m_len >= M2_MIN_LEN);
ip += m_len;
assert(ip <= in_end);
#define M2_OR_M3 (m_len <= M2_MAX_LEN)
#endif /* (DD_BITS == 0) */
if (M2_OR_M3)
{
/* we've found a M2 or M3 match */
assert(ip <= in_end);
/* 2a) compute match parameters */
#if (DD_BITS == 0)
assert(pd(ip,m_pos) == m_off);
--ip; /* ran one too far, point back to non-match */
m_len = pd(ip, ii);
#endif
/* 2a2) verify match parameters */
assert(m_len >= M2_MIN_LEN);
assert(m_len <= M2_MAX_LEN);
assert(m_len <= M3_MAX_LEN);
assert(m_off >= M2_MIN_OFFSET);
assert(m_off >= M3_MIN_OFFSET);
assert(m_off <= M3_MAX_OFFSET);
assert(ii-m_off == m_pos_sav);
assert(lzo_memcmp(m_pos_sav,ii,m_len) == 0);
/* 2b) code the match */
#if (_M2_MAX_OFFSET != _M3_MAX_OFFSET)
if (m_off <= M2_MAX_OFFSET)
{
#else
assert(m_off <= M2_MAX_OFFSET);
#endif
m_off -= M2_MIN_OFFSET;
/* code match len + low offset bits */
*op++ = LZO_BYTE(((m_len - (M2_MIN_LEN - 2)) << M2O_BITS) |
(m_off & M2O_MASK));
/* code high offset bits */
*op++ = LZO_BYTE(m_off >> M2O_BITS);
LZO_STATS(lzo_stats->m2_matches++);
LZO_STATS(lzo_stats->m2_match[m_len]++);
#if (_M2_MAX_OFFSET != _M3_MAX_OFFSET)
}
else
{
#if defined(LZO_HAVE_R1)
#if (M3_MIN_LEN == M2_MIN_LEN)
r1 = ip_end; /* invalidate R1 pointer */
#endif
#endif
assert(m_len >= M3_MIN_LEN);
m_off -= M3_MIN_OFFSET - M3_EOF_OFFSET;
/* code match len */
*op++ = LZO_BYTE(M3_MARKER | (m_len - (M3_MIN_LEN - 1)));
/* code low offset bits */
*op++ = LZO_BYTE(m_off & M3O_MASK);
/* code high offset bits */
*op++ = LZO_BYTE(m_off >> M3O_BITS);
LZO_STATS(lzo_stats->m3_matches++);
LZO_STATS(lzo_stats->m3_match[m_len]++);
#if defined(LZO_HAVE_M3)
m3 = op; /* set M3 pointer */
#endif
}
#endif /* (_M2_MAX_OFFSET != _M3_MAX_OFFSET) */
if (ip >= ip_end)
{
ii = ip;
break;
}
/* 2c) Insert phrases (beginning with ii+1) into the dictionary. */
#if (CLEVEL == 9) || (CLEVEL >= 7 && M2L_BITS <= 4) || (CLEVEL >= 5 && M2L_BITS <= 3)
/* Insert the whole match (ii+1)..(ip-1) into dictionary. */
++ii;
do {
DVAL_NEXT(dv,ii);
#if 0
UPDATE_D(dict,drun,dv,ii,in);
#else
dict[ DINDEX(dv,ii) ] = DENTRY(ii,in);
#endif
MI
} while (++ii < ip);
DVAL_NEXT(dv,ii);
assert(ii == ip);
DVAL_ASSERT(dv,ip);
#elif (CLEVEL >= 3)
SI DI DI XI
#elif (CLEVEL >= 2)
SI DI XI
#else
XI
#endif
}
else
{
/* we've found a M3 or M4 match - see how far we can still go */
assert(ip <= in_end);
assert(lzo_memcmp(m_pos_sav,ii,(lzo_uint)(ip-ii)) == 0);
/* 2a) compute match parameters */
#if !defined(MATCH_IP_END)
assert(ii == ip - (M2_MAX_LEN + 1));
#if (DD_BITS > 0)
assert(m_len == (lzo_uint)(ip-ii));
m_pos = ip - m_off;
assert(m_pos == m_pos_sav + m_len);
#endif
{
const lzo_bytep end;
end = in_end;
while (ip < end && *m_pos == *ip)
m_pos++, ip++;
assert(ip <= in_end);
m_len = pd(ip, ii);
}
assert(pd(ip,m_pos) == m_off);
#endif
/* 2a2) verify match parameters */
assert(m_len >= M3_MIN_LEN);
assert(m_off >= M3_MIN_OFFSET);
assert(m_off >= M4_MIN_OFFSET);
assert(m_off <= M3_MAX_OFFSET);
assert(m_off <= M4_MAX_OFFSET);
assert(ii-m_off == m_pos_sav);
assert(lzo_memcmp(m_pos_sav,ii,m_len) == 0);
/* 2b) code the match */
if (m_len <= M3_MAX_LEN)
{
/* code match len */
*op++ = LZO_BYTE(M3_MARKER | (m_len - (M3_MIN_LEN - 1)));
LZO_STATS(lzo_stats->m3_matches++);
LZO_STATS(lzo_stats->m3_match[m_len]++);
}
else
{
assert(m_len >= M4_MIN_LEN);
/* code M4 match len flag */
*op++ = M4_MARKER;
/* code match len */
m_len -= M4_MIN_LEN - 1;
while (m_len > 255)
{
m_len -= 255;
*op++ = 0;
}
assert(m_len > 0);
*op++ = LZO_BYTE(m_len);
LZO_STATS(lzo_stats->m4_matches++);
}
m_off -= M3_MIN_OFFSET - M3_EOF_OFFSET;
/* code low offset bits */
*op++ = LZO_BYTE(m_off & M3O_MASK);
/* code high offset bits */
*op++ = LZO_BYTE(m_off >> M3O_BITS);
#if defined(LZO_HAVE_M3)
m3 = op; /* set M3 pointer */
#endif
if (ip >= ip_end)
{
ii = ip;
break;
}
/* 2c) Insert phrases (beginning with ii+1) into the dictionary. */
#if (CLEVEL == 9)
/* Insert the whole match (ii+1)..(ip-1) into dictionary. */
/* This is not recommended because it can be slow. */
++ii;
do {
DVAL_NEXT(dv,ii);
#if 0
UPDATE_D(dict,drun,dv,ii,in);
#else
dict[ DINDEX(dv,ii) ] = DENTRY(ii,in);
#endif
MI
} while (++ii < ip);
DVAL_NEXT(dv,ii);
assert(ii == ip);
DVAL_ASSERT(dv,ip);
#elif (CLEVEL >= 8)
SI DI DI DI DI DI DI DI DI XI
#elif (CLEVEL >= 7)
SI DI DI DI DI DI DI DI XI
#elif (CLEVEL >= 6)
SI DI DI DI DI DI DI XI
#elif (CLEVEL >= 5)
SI DI DI DI DI XI
#elif (CLEVEL >= 4)
SI DI DI DI XI
#elif (CLEVEL >= 3)
SI DI DI XI
#elif (CLEVEL >= 2)
SI DI XI
#else
XI
#endif
}
/* ii now points to the start of the next literal run */
assert(ii == ip);
/*
vi:ts=4:et
*/
|
